Coho Salmon (Oncorhynchus kisutch)

• The status of coho populations in the Pacific Northwest varies, with some being healthy and robust while one is listed as endangered and three are considered threatened under the Endangered Species Act. Coho salmon stocks in Alaska are healthy.
• The United States and Canada cooperate in the sustainable management of Pacific salmon through the Pacific Salmon Treaty.
• Coho salmon is low in sodium, a good source of omega-3 fatty acids, and a very good source of protein, niacin, vitamin B12, and selenium. For on more nutrition, see Nutrition Facts. (USDA)
• The United States catches the majority of the world's harvest of coho salmon.

Sustainability Status

Biomass: Unavailable*
Overfishing: No**; N/A***
Overfished: No**; N/A***
Fishing and habitat: Coho salmon are an important species for commercial, recreational, and subsistence fishing. Recreational anglers target coho salmon in both marine and freshwaters. Coho salmon are a target species of commercial troll fisheries in the Pacific Northwest and Alaska. They are also harvested in commercial seine and gillnet fisheries and taken by a variety of gear for subsistence and personal use. Fishing gear for salmon has little or no direct impact on fish habitat; however, lost net gear can pose an entanglement risk to marine animals.
Bycatch: The primary bycatch is other salmon species. Management measures seek to minimize bycatch and bycatch mortality to the greatest extent practical.
Aquaculture: There has been some market aquaculture of coho salmon in both marine net pens and freshwater (for pan-sized fish) in the Pacific Northwest. An extensive network of hatcheries has been constructed in the Pacific Northwest and California to mitigate the effects of hydroelectric or other developments on the availability of quality salmon habitat, and/or assist with the rebuilding of depressed stocks. In Alaska, most coho salmon production is from wild stocks, but in some areas, hatchery production of coho salmon has been developed to provide additional harvest opportunities to recreational and commercial fisheries. Aquaculture to market size is illegal in Alaska.

*Unlike most groundfish stocks, biomass measurements are not used to describe the status of salmon stocks. Instead, stock status is usually described using measures of spawning escapement, productivity, and recruitment. However, annual estimates of abundance of year classes that will contribute to fisheries are used for management purposes.

**Oregon Coastal Natural, Grays Harbor, Queets, Hoh, Quillayute Fall, Western Strait of Juan De Fuca, Eastern Strait of Juan De Fuca, Hood Canal, Skagit, Stillaguamish, Snohomish, and Coho Salmon Assemblage (Alaska) stocks

***Overfishing and overfished criteria are not applicable to some stocks. The Pacific Salmon Fishery Management Plan contains three exceptions to the application of this criteria and subsequent Council actions: (1) hatchery stocks, (2) stocks for which Council management actions have inconsequential impacts, and (3) stocks listed under the ESA. These stocks currently include Columbia River Late (hatchery), Columbia River Early (hatchery), Central California Coast (ESA Threatened 1996), Northern California (ESA Threatened 1997), Columbia River (natural - Proposed ESA Threatened 2004), Willapa Bay (hatchery), Quinault (hatchery), Quillayute Summer (hatchery), South Puget Sound (hatchery), Southern British Columbia Coastal Stocks (2), Fraser River (2).

Science and Management

Coho salmon is one of the main salmon species off the West Coast managed by the Pacific Fishery Management Council through the Salmon Fishery Management Plan (FMP). There are two central parts of the FMP: an annual goal for the number of spawners of the major salmon stocks ("spawner escapement goals"), and an allocation of the harvest among different groups of fishers (commercial, recreational, tribal, various ports, ocean, and inland). Management tools such as season length, quotas, and bag limits vary depending on how many salmon are present each year. The Council must also comply with laws such as the Endangered Species Act.

In Alaska, coho salmon is managed through the FMP for Salmon Fisheries in the EEZ off the Coast of Alaska. The Salmon FMP allows a commercial troll fishery in the EEZ off Southeast Alaska, and closes the remaining EEZ off Central and Western Alaska to commercial salmon fishing. Management of the commercial troll salmon fishery in Southeast Alaska is deferred to the State of Alaska. The Alaska Department of Fish and Game also manages coho salmon in state waters for commercial and recreational fisheries and subsistence and personal use. On Federal lands in Alaska, subsistence use of salmon is managed by Federal Subsistence Boards and the United States Fish and Wildlife Service and Forest Service.

Salmon originating in the lakes and streams in one area or one country often spend a significant part of their lifecycle feeding, growing, and contributing to fisheries in the waters of other jurisdictions. The U.S. and Canada recognized these shared interests and responsibilities for salmon and signed the Pacific Salmon Treaty in 1985 to foster long-term benefits for salmon and to establish processes for the two countries to cooperate in the management, research, and enhancement of Pacific salmon stocks of mutual concern. The Pacific Salmon Commission was formed to implement the treaty and provide regulatory advice and recommendations to U.S. and Canadian management agencies that regulate salmon fisheries. In 1999, an amended agreement under the treaty implemented abundance-based management (rather than based on negotiated catch ceilings) included habitat provisions, created the Transboundary Panel and the Committee on Scientific Cooperation, and established the Northern and Southern Restoration and Enhancement funds. A new, 2008 agreement has been negotiated between the U.S. and Canada and is currently being considered for ratification by the two countries. The Pacific Fishery Management Council manages the Southern British Columbia Coastal and Fraser River stocks consistent with provisions of the treaty.

Life History and Habitat

Life history, including information on the habitat, growth, feeding, and reproduction of a species, is important because it affects how a fishery is managed.

• Geographic range: Coho salmon are found throughout the North Pacific Ocean and inhabit most coastal streams and rivers from Alaska to central California. They are most abundant in coastal areas from central Oregon to southeast Alaska.
• Habitat: Salmon are anadromous, living in the ocean but returning to freshwater to spawn. Coho spend approximately the first half of their life cycle rearing and feeding in streams and small freshwater tributaries. The remainder of the life cycle is spent foraging in estuarine and marine waters of the Pacific Ocean.
• Life span: Usually 3-4 years from egg to adult. After 1-2 years in freshwater, the juveniles develop into smolts and migrate to marine waters, and most coho salmon return to their natal streams after 1.5 years at sea. However, some coho salmon males, called "jacks", return to freshwater at a small size the same year that they migrate to sea as smolts.
• Food: In freshwater, coho feed on plankton and insects; they switch to a diet of small fishes when in the ocean, such as herring, sandlance, anchovies, and sardines. They are also known to eat juveniles of other salmon species, especially pink and chum salmon, and juvenile sablefish.
• Growth rate: Growth in freshwater is relatively slow; it takes 1-2 years for a coho salmon to grow to a 4-5 inch long smolt. In marine waters, however, coho salmon have rapid growth, and are one of the fastest growing Pacific salmon species.
• Maximum size: Coho can grow to more than 2.5 feet in length.
• Reaches reproductive maturity: At age 3 or 4 for most adults, depending on time spent in freshwater prior to smolting; for jacks, age 2 or 3, again depending on freshwater age.
• Reproduction: Adult coho salmon migrate from the ocean into the freshwater streams and rivers where they were born in order to mate. They only spawn once and then die. Females prepare several nests, called redds, in stream bottoms with fairly specific characteristics, including clear, cool water and suitable gravel. The eggs are laid and incubate for six to seven weeks until they hatch into yolk sac larvae. The larvae remain in the gravel until the yolk sac is absorbed. The fry emerge, and after maturing into smolts capable of living in salt water, they migrate downstream to the ocean.
• Spawning season: Adults enter rivers in the fall and winter to spawn.
• Spawning grounds: Smaller streams and tributaries with stable gravel substrates from the San Lorenzo River in Monterey Bay, California to Point Hope, Alaska, and throughout the Aleutian Islands.
• Migrations: Coho salmon are anadromous, meaning they migrate from the ocean into freshwater to spawn. Young fish migrate back to the ocean and remain close to shore. As they grow, they move offshore. Some stocks of coho salmon may migrate more than 1,000 miles in the ocean, while other stocks remain in marine areas relatively close to their natal streams.
• Predators: Juvenile coho are preyed upon by otters, seals, and a variety of fish and avian predators. Adults are eaten by sharks, sea lions and seals, and orcas.
• Commercial or recreational interest: Both
• Distinguishing characteristics: Coho have dark metallic blue or greenish backs with silver sides and a light belly. While they are in the ocean, they have small black spots on their back and upper lobe of the tail. The gumline in the lower jaw has lighter pigment than on Chinook salmon. In freshwater, spawning coho are dark with reddish-maroon coloration on the sides. Spawning males develop a strongly hooked snout and large teeth. Before juvenile coho migrate to sea, they lose their parr marks, a pattern of vertical bars and spots useful for camouflage, and gain the dark back and light belly coloration of coho living in the ocean. Their gills and kidneys also begin to change at this time so that they can process salt water.

Role in the Ecosystem

As with other Pacific salmon species, coho salmon are an important mechanism for transporting nutrients from marine to freshwater and terrestrial ecosystems. Salmon carcasses, as well as eggs, embryos, alevins, and fry, provide nutrients to stream and lake ecosystems. Carcasses have been shown to enhance salmon growth and survival by contributing significant amounts of nitrogen and phosphorous compounds to streams. Additionally, aquatic and riparian plants uptake nutrients from salmon carcasses.

Coho salmon juveniles in freshwater are territorial and aggressive, and are an important factor in fish community structure in their watersheds. In marine waters, coho salmon play a role as both predator on forage fish species and prey for a variety of fish, birds, and marine mammals.

Additional Information

Market names: Salmon, Coho or Silver or Medium Red
Vernacular names: Hoopid Salmon, White Salmon, Silver Salmon, Medium Red Salmon

Biomass

Biomass refers to the amount of coho salmon in the ocean. Biomass estimates are not available for coho salmon. Unlike most groundfish stocks, biomass metrics are not used to describe the status of salmon stocks. Instead, stock status is usually described using measures of spawning escapement (how many fish return to spawn), productivity, and recruitment. Information related to the status of stocks can be found on the websites listed at the bottom of this page.

Landings

Landings refer to the amount of catch that is brought to land.

Biomass and Landings

Are landings and biomass related? Landings are dependent on biomass, management measures in the fishery, and fishing effort.

Data sources:
Landings from NMFS Annual Commercial Landings Statistics using "SALMON, COHO" as Species and "ALASKA" and "PACIFIC" as State

Important Dates

1977 – Pacific Fishery Management Council's first salmon fishery management plan (FMP) issued to govern salmon season
1978 – New Pacific salmon FMP issued to replace 1977 document
1984 – Amendment 6 replaces 1978 Pacific salmon FMP and establishes a framework of management objectives to allow annual management measures to be changed depending on stock abundance or other factors
1993 – Commercial troll fisheries closed to coho retention south of Cape Falcon, Oregon; recreational retention limited
1996 – Central California Coast coho stock listed as threatened under the Endangered Species Act (ESA); retention of recreational catch prohibited to protect this stock
1997 – Southern Oregon/Northern California Coast coho stock listed as threatened under the ESA
1998 – Oregon Coastal Natural coho stock listed as threatened under the ESA
1999 – PFMC modifies Oregon Coastal Natural coho management goals under Amendment 13 to protect and rebuild the stock
2002 – Columbia River natural coho are listed as endangered under the Oregon State ESA
2005 – Columbia River natural coho are listed as threatened under the Federal ESA
2006 – NOAA's National Marine Fisheries Service concludes that the Oregon Coastal Natural coho does not warrant listing under the ESA
2007 – Conclusion regarding threatened listing of Oregon Coastal Natural coho is overruled by a U.S. court decision
2008 – Oregon Coastal Natural coho is relisted as threatened

Notes and Links

General Information:
Pacific Fishery Management Council Backgrounder on Salmon

NOAA's National Marine Fisheries Service (NMFS) Office of Protected Resources Coho Salmon page

NMFS Species of Concern Fact Sheet for Coho Salmon

NMFS Southwest Fisheries Science Center Salmon Ecology Team

NMFS Southwest Regional Office - Recovery of salmon and steelhead in California and Southern Oregon

Fishery Management:
Pacific Coast Salmon Plan and Amendments

Final Amendment 13 to the Pacific Coast Salmon Plan

FMP for the Salmon Fisheries in the EEZ off the Coast of Alaska

Stock Assessments:
Review of 2007 Ocean Salmon Fisheries